For rock reinforcement often two-component resin with hardener is used to fix rock bolts introduced as reinforcement in bored holes in the rock. The resin is supplied in the form of cartridges where the non-hardened resin is enclosed in an outer cover and where hardener in turn is enclosed in a separate part inside the cover. After a suitable number of resin cartridges have been introduced in a borehole a rock bolt is introduced during rotation whereby the cover of the cartridges is teared apart and the non-hardened resin is mixed with the hardener. The rotation of the rock bolt is proceeded until the two-component resin starts harden. The rock bolt will thereby be fixed in its position in the bore hole.
Earlier known arrangements to load a borehole with this type of cartridges often comprises a grouting nozzle with a tube which is brought to abut the borehole to be loaded with cartridges. From this tube a flexible hose leads to a loading tube placed adjacent to a rock drilling equipment. One or several cartridges is placed in loading position in the loading arrangement. Thereafter a pressure medium is supplied to the loading tube and the one, or several, in loading position placed cartridge is fired by the pressure medium through the flexible hose via the grouting nozzle and into the borehole to be loaded. The cartridges are placed manually in firing position in the loading arrangement.
Manual handling of this type of cartridges shall as far as possible be avoided since the two-component resin is very insanitary. Several proposed solutions for automatically feed and fire this type of cartridges have been proposed. This type of cartridges is however difficult to handle since their outer cover is relatively soft and they thereby have a kind of formless shape. Another problem with the soft cover is that the cartridges relatively easy may tear apart. A comprehensive cleaning of the feeding means from spilled both non-hardened and hardened resin is then necessary which generally causes a longer stop in operation. Further, variations in the size of the cartridges may occur which further causes problem. The surface of the cartridges is also of such nature that they may easy adhere to each other which also causes problem when automatically feeding.
U.S. Pat. No. 6,390,189 is an example of automatically feeding means for cartridges intended to be used with a rock drilling equipment. The known arrangement comprises a rotatable cartridge storehouse provided with a plurality of loading tubes arranged along with the periphery of the storehouse. The cartridge storehouse may be loaded in advance with a large number of cartridges. The storehouse is thereafter rotated stepwise whereby one in a loading tube placed cartridge is brought into firing position. By applying compressed air to the loading tubes, the cartridge is fired away from the loading tube via a connecting hose positioned in the firing direction and further into a bore hole.
The known arrangement however shows a plurality of disadvantages. Many separate loading tubes makes the design large, heavy and clumsy, and expensive and complicated to manufacture. Further, it does not manage to handle cartridges of different dimensions. If a cartridge tears apart, the storehouse with its complex design is difficult to clean with long down time following. The design further causes that the cartridges must be handled one by one when loading the storehouse.
Another example of automatically feeding means is shown in US 2008/0145152. The known arrangement comprises one or several containers comprising cartridges arranged horizontally laying on each other, and placed above a loading area being in connection with a firing area for the cartridges. Between each container and the loading area is a rotating distributor arranged to move the cartridges one by one.
The V-shaped designed containers which uses gravity for feeding causes that a cartridge is exposed to large weight from above laying cartridges when the storehouse is loaded with many cartridges. During feeding the cartridge is at the same time exposed to friction against the sides of the design and to the above and below placed cartridges. This causes a risk that some of the cartridges tears apart with subsequent down time. The design is complex with both fixed and movable parts which makes it difficult to clean.
A further known arrangement is shown in WO 99/64722. Also in this design cartridges is fed with help from gravity. The cartridges that is located far down are thus also in this feeding means exposed to large weight from above placed cartridges and to friction against the sides of the design and from above and below placed cartridges. The design is complex and comprises movable parts which makes it complicated to manufacture and difficult to clean.